Answer:
To find the concentration of HNO3, we can use the equation for the neutralization reaction between HNO3 and NaOH:
HNO3 + NaOH -> NaNO3 + H2O
From the balanced equation, we can see that the stoichiometric ratio between HNO3 and NaOH is 1:1. This means that the number of moles of HNO3 is equal to the number of moles of NaOH used for neutralization.
Given the volume of NaOH used (0.18 L) and its concentration (0.1 M), we can calculate the number of moles of NaOH:
moles of NaOH = concentration of NaOH * volume of NaOH
= 0.1 M * 0.18 L
= 0.018 moles
Since the stoichiometric ratio is 1:1, the number of moles of HNO3 is also 0.018 moles.
Now, we can find the concentration of HNO3:
concentration of HNO3 = moles of HNO3 / volume of HNO3
= 0.018 moles / 0.26 L
≈ 0.0692 M
Therefore, the concentration of HNO3 is approximately 0.0692 M.
Step-by-step explanation: